Calculating-machine.



Pa tented Dec. 30, 1962.

DE KERNIEA J. T. HIETT.

CALCULATING MACHINE.

(Application filed FEB. '24, 1902.)

9 Sheets-Shet I.

(No ModeL) m: NORRIS vz'rzks w. morouwou wxsulmww. 0. c.

No. 7|7,396. Patented 080,30. I902.

DE KEBNIEA J. T. HIETT. CALCULATING MACHINE.

(Application filed Feb. 24, 1902.)

(No Model.)

9 Sheets.-Sheai 2.

Tu: mums PETERS co. PHOTO-UTHO" wAsumcrow, n. cy

Patented Dec. 30, I902.

DE'KEBNIEA .1. T. HIETT.

CALCULATING MACHINE.

(Application filed Feb. 24, 1902.)

9 Sheets-8heet 3.

(N0 Model.)

I WMaea THE norms mznsco. PNOTQ-LITHO, WASHXNGTON. 0.1:

Patented Dec. 30, 1902.

No. 7l7,396.

DE KERNIEA J. T. HIETT.

CALCULATING MACHINE.

(Application filed Feb. 24, 1902.)

9 Sheets-Sheet 4.

(No Model.)

No. 717,396. Patented Dec. 30, I902.

DE KERNIEA .1. T. HIETT.

CALCULATING MACHINE.

' Application filed Feb. 24, 1902.] (No Model.) 9 Sh'eets-Sheet 5,

m: norms vz'rsns co, PMOYO-UTHO, wAsmNaTon, n. c

9 sham-sheet e.

' No. 717,396; Patented Dec. 30, I902.

DE KERNIEA J. T. HIETT.

GALBULATI'NGMAGHINE. (Application filed Feb. 24, 1902.) (No Model.)

a M a Ratented'Dec. 30', I902.

Nu. 7l7,396.

DE KERNIEA J. T. HIETT.

CALCULATING MACHINE.

(Applicatinnfiled Feb. 24; 1902.)

, 9 Sheets-Sheet 7 (No Model.)

2 SM \wm ixJQT rm$ m 0 1: uc'mms PETERS is, Pumaur na, vmsnmm'ou. u. c.

Patented.Dec. 30, I902.

'No. 7l7,396.

DE KERNIEA J. T. HIETT.

CALCULATING MACHINE.

(Application filed Feb. 24, 1902.)

9 Sheets-Sheet 8.

(No Model.)

3 cc. Pkcrauma. wuamm'ou, n c.

, Patented Dec. 30, I902: DE KERNIEA J. T.'HIETT CALCULATING MACHINE.

(Application filed. reb. 24, 1902.)

9 Sheets-8heet 9.

(No Model.)

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"HE NBRRIS PETERS co, vuorauma. wnsnmc'rou, 04 c.

UNITED STATES PATENT OFFlCEQ DE KERNIEA J. T. HIETT, OF ST. LOUIS, MISSOURI, ASSIGNOR OF THIR- TEEN'TWENTY-FIFTHS TO GUSTAVUS A. VON BREOHT, OF ST. LOUIS,

MISSOURI.

CALCU LATIN G-MACH'I N E.

SPECIFICATION forming part of Letters Patent N 0. 717,396, dated December 30, 1902- Application filed February 24, 1902. Serial No. 95,343- O mo el- T0 ctZZ whom it may concern:

Be it known that LDE KERNIEA J.-T.H1n'r'r, a citizen of the United States, residing atSt. Louis, in the State of Missouri, have invented certain new and useful Improvements in Oalculat'ing-lvlachines, of which the following is a full, clear, and exact specification.

This invention relates to improvements in calculating-machines, and refers more specifically to improvements in that type of calculating-machines which are used by accountants for recording and printing numerical items, for performing a mechanical addition of the sums of a plurality of items, and recording and printing these aggregates or totals, and for various other computations, as will hereinafter more fully appear.

Among the salient objects of the invention are to provide a machine of the character referred to in which all of the mechanical connections and movements of the correlated parts are positive and certain as distinguished from machines of this same general character in which the movement of cooperating parts has depended upon springs, friction devices, retarding devices, and the like; to provide a key-actuated setting-up mechanism which is absolutely independent in its operation of all other parts of the machine and in which the operation of each key serves to place a member or part in position to become an element of a positively-operating mechanism which subsequentlydetermines or eitects the recording or-printing of a numeral corresponding to the key actuated; to provide in a key mechanism adapted for a machine of this general character a'construction in which the keys are arranged in correlated groups representing the diiferent orders of numerals and means are provided for automatically clearing or restoring any key of a given group by simply operating another key of the same group and withoutin any wise affecting the keys of other groups; to provide improvements in the construction and arrangement of the bank of keys of a machine of this character contributing to the accuracy and speed of operation, to the durability and neatness of appearance of the mechanism, and greatly improving the touch of the machine; to

provide a construction in which the keys and key mechanism pertaining to each group or order of keys are mounted upon the same structural supports, so that machines of different capacities or numbers of orders may be built by simply adding to or leaving off a greater or less number of unit groups and in which the inspection, repair, and assemblement of the machine is facilitated; to provide an improved recording or printing mechanism in which the printing is effected by means of type-carriers independently movable and one for each group or order of keys and the actuation or selection of the type members which are to be brought into action upon any given operation is determined by means of novel mechanism; to provide in a printing mechanism of this general character improved means for insuring the actuation of every printing member or carrier to the right of or of a lower order than the numeral of highest order set up, thereby insuring the printing of the naughts of the intervening and lower orders; to provide in a printing mechanism adapted to a machine of this general character means for bringing the printed members or carriers into printing engagement successively, so as to distribute the power required to effect the impressions over a substantial part of the movement of the actuating devices; to provide in a printing mechanism of this general character a construction in which the power required to operate the printing mechanism and produce the impression is directly proportional to the number of printing members brought into operation; to provide in a machine of this general character mechanism cooperating with the impression mechanism to expose to view or render visible the items immediately following the printing operation; to provide suitable cooperating mechanism for carrying into eit'ect the several objects of the present invention as hereinbefore stated and as appears from the following description, and in general to provide improved features of construction and arrangement contributing to the production of an improved machine of the character referred to.

In the accompanying drawings, Figure 1 is a vertical longitudinal sectional view through a machine embodying my invention, certain parts being broken away to disclose under lying parts and other parts being omitted. Fig. 2 is a sectional plan view with certain parts broken away and others omitted and the outer casing of the machine being removed. Fig. 3 is a transverse vertical sectional view substantially on the line 3 3 of Fig. 1 looking in the direction of the arrow, the outside casing being removed and certain parts broken away to disclose underlying mechanism. Fig. 4 is a rear end view with the casing removed and certain parts broken away and others omitted. Fig. 5 is a top plan view of the entire machine, more particularly disclosing the key-manual. Fig. 6 isasideelevation, with the casing removed, of certain parts of the mechanism. Fig. 7 is a view generally similar to Fig. 6, but showing certain parts of the mechanism in different operative positions. Figs. 8 and 9 are side elevation and plan views, respectively, in isolated detail, of one of the key-lever-supporting frames employed in the machine; and Figs. 10 to 18, inclusive, are details of the connectors arranged in graduated series from the smallest to the largest. Fig. 19 is a View, partly in side elevation with the casing removed and partly in longitudinal vertical section, showing particularly the arrangement of the accumulators and cooperating mechanism. Fig. 20 is a fragmentary front elevation of the impression-levers, type-carriers, and platen and fulcrum-plate, the overlying adjustable plate being removed and showing particularly the construction and arrangement of the fulcrum-plate proper. Fig. 20 is a fragmentary face view of a portion of a stepped cam-bar. Fig. 21 is a detail in top plan of the set of impression-levers, type carriers, and cooperating fulcrum-plate and plate-support.

Although the present invention concerns more particularly the construction of the keyboard mechanism, the impression mechanism, and certain features cooperating therewith, yet nevertheless a comprehension of these features requires an understanding of their application to a complete adding-machine, and the entire machine will therefore be described herein, the description of those features not made the subject of claims in the present case being made as brief as consistent with a complete understanding of the invention.

Referring then to the several figures of the drawings, 1 designates as a whole a suitable base-plate, having a .horizontal top surface and adapted to rest on any suitable support, and upon the rear portion of this base-plate is secured the main frame structure of the machine. In the present instance apair of skeleton side plates (designated 2) are provided, one at each side of the machine these plates being arranged in parallel relation and being exact duplicates of each other. At their lower ends said side frames are made rigid with the base-plate in any suitable manner as, for example, by being provided with feet portions 3, which are secured or bolted to the base-platewhile at their upper edges they are conveniently made rigid with each other by means of a cross frame member 4, in the present instance taking the form of a horizontal plate let into the upper edges of the side frame members and suitably bolted thereto. Between and upon said side frame members are mounted the impression mechanism, the accumulator mechanism, the carrying mechanism, and the recording-sheet mechanism, which several features will hereinafter be more fully described. The baseplate is extended beyond the forward ends of the side frame members a considerable distance, and upon thisis mounted the keyboard and setting-up mechanism, which Will first be described in detail.

Referring more particularly to Fig. 1, the numeral 200 designates each of a series of plate-like supports mounted to extend longitudinally of the machine, with their planes vertical and in parallel relation, there being one of these supports provided for each group of keys representing an order of numerals. In the preferred construction shown herein said supporting members are made rigid with each other by means of a pair of tie-rods 201 and 202, inserted through the front and rear ends thereof, the individual supports being.

suitably spaced apart by means of spacingsleeves 203 and the outermost ones being secured in position by means of suitable nuts threaded upon the ends of the tie-rods. By means of this construction the supports, together with the parts mounted upon and cooperating therewith, may be assembled and placed and removed as a single structure. The key structure as a whole is suitably secured in position on the base-plate, conveniently by means of bracket-legs 204, formed integrally with the plate-like supports, arranged to rest directly upon the base, and secured to the latter by means of bolts or screws 205.

Inasm uch as the several groups of keys and their supports are identical in structure, the description of one will apply to all.

206 designates each of a series of angular key-levers, there being nine of these levers in the series, suitably mounted upon the upper portion of the support 200, so as to oscillate in vertical planes, these key-levers being for convenience of structure and arrangement disposed alternately on opposite sides of the support and uniformly spaced apart throughout the length of the latter. Each key-leveris provided at its upper end with a horizontal extension or lug 207, adapted for engagement by the lower end ofa key, as 208, while at its lower end it is likewise provided with a horizontal lateral extension or lug 209, certain of which lugs are adapted for engagement with an actuating-rod 210. The lugs 209 of the key-levers are successively longer from the foremost keylever rearwardly and in each instance desirably extend laterally outward in a direction away from the support upon which the key-lever is mounted in order to bring the ends of the lugs severally. vertically above a series of connectors, (designated 211.)

As best shown in Fig. 1, the connectors 211 each consist of a bar or plate-like member arranged with its plane vertical and to extend longitudinally beneath the corresponding connecting-rod 210 from the front portion of the key mechanism rearwardly to a point contiguous to the mechanism contained within the main frame of the machine, each group of nine connectors being arranged side by side, as shown clearly in Fig. 1. The five connectors which are engaged with the five rearmost keys of the group are severally provided at their forward ends with laterally-extending lugs 212, adapted for engagement with the several rods 210, while the four remaining ones of the group are provided with upstanding integral lug portions 213, which are directly engaged by the laterally-extending lugs 209 of the corresponding key-levers, thereby dispensing with the necessity of connecting-rods as to these key-levers.

The connectors are so mounted as to be capable of an endwise-reciprocatory movement and also a lifting-up movement about a pivotal axis located near their forward ends, and to this end each connector-bar is provided at its forward end with a longitudinally-extending slot 21 1, which embraces or engages a pivoting guide-stud 215, mounted rigidly in the support 200, said stud 215 being in the present instance arranged to extend through the supporting-plate and project at either side thereof a sufficient distance to support the several connectors belonging to the group at the respective sides thereof. At their forward ends each connector is provided with a shoe-like lower surface 216, which is arranged to rest and slide upon a plate 217, resting upon the base-plate 1.

The depression of any one of the keys of a given group operates to oscillate its key-lever and through the action of the latter to thrust the corresponding connector bodily rearward. The bodily rearward movement of the connector is efiected against the tension of a suitable spring, tending to return the same to its normal forward limit of movement, said springs being in the present instance in the form of coiled contractile springs 218, which are conveniently adapted to depending lugs 219, formed upon the connectors, and extend thence obliquely downwardly and rearwardly and are connected to suitable stationary supports 220, in the present instance formed integrally upon the supporting-plate 200. In order to hold any given connector at its forward limit of movement after it has been shifted forwardly by the depression of a key, I provide a platespring 221, mounted upon the base-plate be- 'neath the group of connectors and arranged of movement of the connector with a shoulder 223, adapted for engagement with the end of said spring to hold the connector in advanced position, it being noted that the shoulder 223 is located slightly below the normal position of the free end of the spring, so that as the connector is forced rearwardly the spring will be correspondingly depressed until it is permitted to rise into engagement with the shoulder or notch 223.

Next describing the means whereby the actuation of any given connector serves to place it in position to be selected and to be made temporarily an operative member of a positive driving connection, which subsequently serves to actuate the printing and other mechanisms, each connector is provided at its rear end with a book, as 224:, the hooks of the several connectors being arranged to stand in successively lower planes from the connector which corresponds to the numeral 1 and which stands the highest to the connector which corresponds to the numeral 9, which stands lowest. In the particular construction shown herein these hooks are formed upon extensions at the upper edges of the respective bars and project rearwardly, each hook terminatingin a downturned extension or lip 225. Inasmuch as the member which serves to engage the several books is in the present instance caused to travel in an arc, the said hooks are shown in the present instance as arranged to stand in a corresponding arc, so that when any given connector is shifted rearwardly it may be engaged independently of all of the others of that group. Describing now the particular mechanism employed for selecting and lifting said connectors, 226 designates a main rock-shaft arranged to extend entirely across the machine and journaled at its respective ends in suitable pillow-blocksorjournals, (designated as a whole 227 and best seen in Fig. 2.) Said main shaft is provided at a suitable point adjacent to each end with arigid crank-arm, as 228, said crank-arms being arranged to extend parallel with each other and each provided at its outer end with a rigid stud, as 229, which are severally adapted to engage and actuate two peculiarly-shaped cam-levers, (designated as a,

whole 230,) which are likewise counterparts of each other and arranged in parallel relation. The cam-levers 230 extend rearwardly to and are journaled upon pivot-studs 231, mounted upon the side frame members in axial alinement with each other. The lower edges of the front end portions of said cam-levers, which are engaged and acted upon by the cam-studs, are of peculiar configuration, the construction being such that when the studs pass into engagement with said levers they first act upon downwardly and forwardly inclined surfaces 231, therebyimparting a relatively rapid lifting movement to the cam-levers until the lat ter have reached their uppermost limits of movement, after which the studs pass into engagement with curved cam-surfaces 232, which are so formed as to extend concentric with the axis of the main shaft when the camlevers have reached their said uppermost limits of movement, so that during the'further rocking of said main shaft said cam-levers remain stationary.

Next describing that member which serves to select or pick up those ones of the several groups of connectors which have been actuated or set up for any given operation or recording of items, this device is in the present instance essentially a lifting-bail and comprises a pairof arms, (designated 233,) one at each side of the, machine, as best seen in Fig. 2, which are pivotally mounted or connected at their forward ends near the front end of the machine upon suitable upstanding brackets or supports 23st, (see Fig. 2,) the pivotal axes of said arms being arranged in alinement with each other and concentric with the pivotal axis of the several connectors. At their rear ends said bail-arms are rigidly connected by means of a cross-bar 235,

which is suitably shaped to engage with the connector-hooks 224, being desirably and as shown in the present instance approximately L-shaped in cross-section and provided at the forward edge of its lower flange with an upstanding lip or flange 236, adapted to interlock with the several connector-hooks to hold the latter positively from being retracted by their respective springs 218 after they have been lifted out of engagement with the holding-spring 221 and before they have been intentionally released. A driving connection is provided between the cam-arms 230, hereinbefore described, and the bail member last described, which consists in the present instance of a pair of studs 237, one upon each bail-arm, arranged to project laterally outward from the latter and engaging a corresponding slot 238 in the adjacent cam-arm. The slot-and-stud form connection described is adopted to provide for the necessary relative movement of the parts, owing to their axes of oscillation being located at different points.

The main shaft 226 is provided with a crank-handle 226 outside of the frame of the machine, whereby it may be oscillated to rock the arms 228 thereof upwardly and forwardly, and it follows from the construction described that when said main shaft is thus oscillated the cross-bar 235 of thelifting-bail will engage and lift all such connectors as have been shifted rearwardly by the operation of a key, and therefore project beyond erases their normal positions, carrying said connectors upwardly about their pivotal axis until the lifting-bail reaches its uppermost limit of movement. The connectors will there= fore be lifted varying distances, depending upon the normal plane of their several lifting-hooks, the units-connectors being lifted a minimum distance and the other connectors proportionately greater distances. In this connection it will be noted that the normal position of the engaging portion of the lifter-bail 235 is below the normal or lowest position of the lowest ones of the connectors, and it follows that upon the return movement of the lifting-bail to its normal position the connectors will successively go into hearing at their lower edges with the plate 217, and be thus arrested and freed from engagement with said lifter-bail. Inasmuch as each connector is shifted rearwardly at the time it is set by the key a sufficient distance to carry the inner side of its lip 225 slightly beyond the inner side of the engaging lip 236 of the lifting-bail, it follows that as soon as the connector has been lifted out of engagement with the holding-spring 221 the connector will be retracted slightly and until arrested by the lip 236, so that upon the return movement of the lifter-bail the holding-sprin 221 will not reengage the shoulder 223 of the connector, and consequently when disengaged from the lifter-bail will be at once returned to its normal position under the action of its retracting-spring 218.

To next describe the connections whereby the lifting of the connectors is made to positively actuate type-carriers, and referring more particularly to Figs. 1 and 2, 300 designates a series of pairs of guide-rods mounted to extend vertically in parallel relation between the cross frame member 4.- andacorresponding space plate or support 4:, located at the bottom. of the machine and resting upon the base-plate, there being a pair of these guide-rods for each group of keys or order of numerals and the members of each pair being conveniently in longitudinal alinement. Upon each pair of guide-rods is mounted a sliding frame, designated as a whole 301 and consisting in the present instance of a U-shaped member, the upper and lower arms 302 and 303 of which are apertured to fit upon the guide-rods and serve as supports, to which is connected a rack member 400, while the vertical portion 305 of said frame serves to unite said upper and lower members rigidly with each other and serves also as a support fora bracket-like extension 306 at the forward side thereof near the upper end of the sliding frame. Upon the lower portion of each sliding frame 301 is mounted or formed a transversely-extending yoke or channel member 307, which in the normal or lowermost position of said sliding frame stands horizontally opposite the 10 wer portion of the rear ends of the group of connectors pertaining to this particular sliding frame.

Each connector is provided at its said rear end with a knuckle-like extension 308, which is of a vertical Width substantially equal to the vertical width of the channel 309, formed in said yoke member, and is adapted when the connector is shifted rearwardly to enter said channel and form a positive driving connection between the connectorand sliding frame.

Referring more particularly to Fig. 2, it will be seen that the several brackets 306 of the several vertically-sliding frames 301 are extended laterally from their respective frames, so as to approach the central portion of the machine, at which place the carriers are grouped together as closely as may be in order to record upon a comparatively narrow strip or ribbon. Said brackets 306 are not only extended laterally and upwardly, but also have their extreme ends extended forwardly from the respective carriers, so as to stand in parallel relation, and are also suitably spaced apart to bring the type-carriers into proper relation to indicate the proper periods to distinguish between units, hundreds, thousands, the. Each bracket serves as a support, upon which is pivotally mounted a vertically-disposed type-carrier, (severally designated 310,) each being pivoted to its corresponding bracket, as indicated at 311, and extending thence upwardly in front of and adjacent to a suitable printing roller or platen 312. Each type-carrier 310 carries a vertically-disposed row of type 313, representing in the present instance the numerals from 0 to O, inclusive, the numeral 0 being in the normal position of the carrier opposite the printing-point. The type are in the present instance shown as formed or mounted directly upon those edges or faces of the carriers next to the platen; but it is to be understood that the type may be loosely or movably mounted thereon, if preferred. The group of carriers as a whole is normally held retracted a slight distance, so as to permit the inking-ribbon and recording-strip to move freely across the platen con venientlyby means of a plate-spring 314, made of sufficient width to act upon all of the group of carriers and suitably mounted uponacross-bar315. It will be understood that the extreme distance of travel of each vertically-sliding frame is equal to the length of the vertical row of type upon its type-carrier, or, in other words, sufficient to carry the carrier from its normal position upwardly far enough tobring its lowermost type opposite the printing-point.

Next describing the mechanism whereby the typecarriers are forced into printingimpression, with the recording-sheet interposed between said carriers and the platen, it will be understood that this mechanism may be varied without departing from the broader scope of the invention; but in the presentinvention I have shown an improved mechanism for this purpose, which will be made the subject of claims.

Referring again to Fig. 1 of the drawings,

316 designates a supporting-bar, in the present instance taking the form of a rod and arranged to extend across the central portion of the machine a short distance in front of the type-carriers, the ends of this rod being supported by a pair of brackets 317, mounted upon a cross-plate. Upon the support 316 are mounted a plurality of impression-levers 318, one for each of the type-carriers, these impression-levers being provided with transverse slots at points intermediate of their length, which slots embrace the support 316 and being held in suitable alinement with their respective type-carriers by intervening washers. At their upper ends said impression-levers are curved rearwardly and terminate in rounded nose portions 319, adapted to engage proximate edges of the type-carriers to force the latter rearwardly,while at their opposite orlower ends said impression-levers are provided with cam-surfaces 320, adapted for engagement by a cam member 321, provided with a'series of cam-surfaces 322 and in the present instance taking the form as a whole of a bail. Describing said actuating device more particularly, it comprises a pair of arms 323, arranged to extend in approximately horizontal direction rearwardly to and rigidly connected with a rock-shaft 32a, while at their forward or swinging ends said arms are connected by means of a transverse bar or bail member 325, upon the outer or forward face of which are mounted or formed cam-surfaces 322, hereinbefore referred to. In the particular instance shown herein these cam-surfaces consist of a series of inclined steps 322, (see Fig. 20%) which are arranged in successively lower planes from one side of the series of impression-levers to the other, so that said cam-sur-. faces act successively or consecutively upon the latter, each step or cam-surface being inclined forwardly and downwardly, so that as the bail rises the lower ends of the impression-levers will be forced outwardly and the upper ends thereof forced into bearing with the type-carriers. Describing now the mechanism whereby said bail is lifted, and referring more particularly to Fig. 2, 326 designates a toggle-arm pivotally mounted at its forward end, as indicated at 327, upon a suitable bracket lug or support and arranged to extend longitudinally and vertically above a crank-arm 328, rigidly mounted upon the main shaft 226, in the present instance adjacent to the arm 228 thereof,.remote from the handle end of said shaft. The crank-arm 328 is provided with a wrist or stud 329 and is disposed in such angular relation to the main shaft that during the latter part of the movement of said main shaft in its forward oscillation said stud will engage an inclined camsurface 330, formed upon the lower edge of said toggle member, (see particularly Fig. 1,) and will force said toggle member upwardly. To the rear end of the toggle-arm 326 is pivotally connected a second toggle member or link 331, which extends upwardly to and is connected with a stud or wrist 332 upon one of the arms 323 of the bail, adjacent to the cross-bar 325 thereof.

Inasmuch as it is desirable that only those type-carriers should be actuated which correspond to the numbers which have been set up by the actuation of the keys, means are provided whereby the impression-levers 318 are rendered functionally inoperative during each operation, except as to such as are necessary to print the required numbers. To this end I provide a shiftable fulcrum member, (designated as a whole 333,) which is adapted to be shifted out of register with those of the impression-levers which are to remain functionally inoperative during each operation. In the present instance said fulcrum member takes the form of a plate provided at its lower side with rearwardly-extending ears 334, which are engaged with and slide upon a rod and support 335, which, as best shown in Figsland 3,is supported at its endsin suitable brackets 336, formed integrally with a crossbar or support 337, which extends entirely across the machine and is secured to the front vertical edges of the side frames. Atits upper edge the fulcrum-plate is provided with a rearwardly-extending flange 338, the edge of which is rounded and forms the fulcrum proper, against which the impression-levers rest and upon which they oscillate during their functional operation. Upon its lower part said fulcrum-plate is also provided with a rearwardly or inwardly extending fingerlike projection 339, and in the normal position of the latter, which is opposite the set of impression-levers, said finger extends into a position transverse to the vertical plane of the front edges of the vertical portions of the brackets 306, which carry the several typecarriers. It is to be noted, however, that in the normal or lowermost position of said bracket members 306 the finger 339 stands just above their upper ends, so that the folcrum-plate is free to be shifted laterally Without engaging said brackets. When, however, these brackets are carried upwardly by the upward movement of the sliding frames upon which they are mounted, they will be carried into the path of the finger 339 and will serve to arrest the latter, and in case several of these brackets are thus elevated that one of said brackets nearest the left-hand side of the machine and which has been operated will arrest the movement of the fulcrum-plate toward the right-hand side of the machine.

Means are provided for shifting the fulcrum-plate upon each printing operation of the machine, such means comprising yieldable connections which tend to shift the fulcrum-plate the full extent of its throw or to a position entirely out of register with the impression-levers, but permitting the fulcrumplate to be arrested byany one of the brackets 306 in the manner hereinbefore described. In the preferred embodiment shown herein the means for thus shifting the fulcrum-plate comprise a bell-crank lever 340, pivotally mounted at its angle at the right-hand side of the machine and approximately in transverse alinement with the fulcrum-plate, so as to oscillate in a transverse vertical plane, and yieldably connected at its upper end with the fulcrum-plate by means of a coiled contractile spring 341. The lower arm 342 of said bell-crank lever is arranged to project inwardly above an operating-lever 343, which is arranged to rise and act upon said arm 342 during each reciprocation of the main shaft. To this end said operating-lever 343 is in the form of a bar, which extends forwardly to and is pivotally mounted upon a bracket 344 (see Fig. 2) and is provided at a point intermediate its length upon its lower edge with an inclined cam-surface 345, adapted to be engaged by a stud or pin 346, mounted upon the crank-arm 228 at that side of the machine. The position of the inclined cam-surface 345 relatively to the throw of the crank-arm is such that the lever 343 will not be actuated until after all of the type-carriers and the brackets which carry the latter have been moved upwardly far enough to carry them within the path of the finger 339. In other words, the movement of the lever 343 occurs almost at the end of the movement of the crank-arm 228 in its advance movement. The result of this construction is that upon each recording or printing operation of the machine the fulcrumplate will be withdrawn or carried out of register with all of those impression-levers 318 which are to the left of the key of highest order operated, and when the actuating-cams 322 are carried upwardly to oscillate the impression-levers those of the latter from behind which the fulcrum-plate has been drawn will simply swing outwardly on the guide-bar or support 316 by reason of their slotted connection therewith and will not be brought into operative bearing with the carriers. In order that the fulcrum-plate 333 may be returned to its normal position, a slotted actuating-bar 340 is pivotally connected with the upper end of the angle-lever 340, the slot of which bar engages a suitable stud 333 upon the fulcrum-plate and operates to positively return said plate with the return movement of the lever. A coiled spring 341, connecting the upper end of the lever 340 with the cross frame member 337, operates to return the lever 340 to its normal position. In order to hold the impression-levers 318 in a normally retracted position, each of the latter is provided with a spring, as 347, suitablysecured to its front side and arranged to bear against a cross-rod or support 348, carried by extensions of the brackets 317.

Inasmuch as the springs 347 cooperate with the cam-bar 321 to thrust forward idly those impression-levers from in front of which the fulcrum-plate has been withdrawn, it is necessary to provide for returning said impression-levers out of the path of the fulcrumplate in the return operation of the latter. This is accomplished by beveling the edge of the fulcrum-plate, as indicated at 33S in Fig. 21, so that it rides over the impression-levers show fashion and returns them to their normal positions during the return movement of the fulcrum-plate.

In order to adjustably support the upper portion of the fulcrum-plate 333, I desirably provide a supplemental plate 34.), adjustably mounted upon the cross-bar 337 and secured thereto by means of adjusting-screws 350, the lower edge of said plate being provided with an inwardly-extending flange or bead 351, which forms a fulcrum which rests against the cross-bar 337, while its upper edge is provided with a somewhat similar head or bearing-rib 352, which forms the fixed point or hearing against which the fulcrn m-plate rests. Obviously by adjusting the screws 350 inwardlyor outwardly the upper portion of the fulcrum-plate will be advanced or retracted accordingly and the throw of the impressionlevers correspondingly varied.

The particular mechanism whereby the recording-strip is supported and fed around the roller-platen 312, hereinbefore referred to, to receive the impressions of the type forms no part of the present invention, but, on the contrary, forms the subject-matter of a separate application filed contemporaneously herewith, Serial No. 95,345, and will therefore be but briefly referred to herein. Said mechanism comprises a feed-roller 353, which is suitably driven step by step in the usual manner and serves to draw forwardly the recording-stri p 354, which passes between said feedroller and the impression-roller, the supply end of the recording strip or sheet being held bya traveling carriage designated as a whole 355 and which is mounted to slide forward upon a pair of guide-bars 356, suitably supported in the upper portion of the framework in horizontal and parallel position.

357 designates the inking-ribbon, the position of which is merely indicated and which may be supported in operative position by means of any preferred ribbon mechanism.

The accumulator and carrying mechanisms forming parts of the present machine are also made the subject of a separate application filed contemporaneously herewith, Serial No. 95,344, and reference is made to said application for a specific description of these mechanisms. Inasmuch, however, as an understanding of the construction and operation of these mechanisms will contribute materially to a full comprehension of the features of invention described and claimed in the present application, the following description is added, which is made sufficiently comprehensive to enable these mechanisms to be understood.

400 designates a series of racks which, to economize space, are mounted in offset relation one upon each of the sliding frames 301,

so as to move up and down with the latter.

401 designates a transversel y-extendin g crossbar mounted to have a limited endwise or transverse movement, being to this end provided at each end with longitudinally-extending slots 402, (see Fig. 3,) which engage supportingstuds 403 upon the main side frames.

404 designates a second transversely-extending support or bar rigidly mounted to extend between the main side frame members in parallel relation to the support 401. \Nithin these two supports is mounted a series of accumulator-shafts 405, one for each of the several racks 400, carried by the verticallysliding frames, these accumulator-shafts being journaled at their rear ends in the support 404 in bearing-apertures 406, which are sufficiently elongated orloose to afford a slight swinging movement of the opposite ends of the shafts in a lateral direction. The forward ends of the accumulator-shafts are loosely journaled in the supporting-bar 401 and are provided at their extreme forward ends with pinions 407, respectively arranged to mesh with the several racks 400.

Upon each accumulator-shaft is mounted an accu m ulator proper, (designated 408,) preferably and as herein shown taking the form of a drum or cylinder provided with a spirally-arranged series of radially-extending lugs or projections 409, corresponding in number to the several digits and spaced at uniform angular distances apart around the circumference of thetdrum with the exception of one space or interval which is left blank and which corresponds with the O in the series of digits.

The several accumulators are splined upon the accumulator-shafts. In order to insure their movement together back and forth along the accumulator-shafts, a confiningframe is provided, comprising front and back bars 410 and 411, mounted upon the accumulator-shafts adjacent to the ends of the accu mulators and united at their ends by means of integral tie portions 412, as best seen in Fig. 2. The object of so mounting the forward ends of the accumulator-shafts in the support 401 that the series of shafts may be moved bodily and together is in order to throw the pinions thereof into and out of mesh simultaneously with their respective racks, it being understood that during one movement of the sliding frame the racks are engaged with the pinions and advance or rotate the accumulators an angular distance proportionate to the distance of travel of the respective sliding racks, while upon the opposite movement of thelatter the pinions are thrown out of mesh, so as to leave the accumulators standing in the several positions to which they have been rotated.

Describing next the mechanism for automatically and positively shifting the accumulator-shaft pinions into and out of mesh each time the main shaft is operated, and referring more particularly to Figs. 2 and 3, 413 designates a rock-shaft journaled in vertical position to extend between the frame members 4 and 4 and provided at a point intermediate its length with a rearwardly-extending rigid finger or projection 414, which extends between the forks of a depending bracket 415, mounted rigidly upon thereciprocatory bar 401. Upon the lower portion of the rock-shaft is mounted a second peculiarlyshaped bracket 416, which is adapted to be acted upon by the extreme end of a lever 417, which extends from a point opposite the rock-shaft forwardly to and is pivoted upon the bracket 344, hereinbefore described; The lever 417, as best seen in Fig. 6, is of peculiar shape, being provided at a point intermediate its length with an upwardlyarched portion 418, the lower edge of which forms a cam-surface. The cam-surface last referred to is adapted to be engaged by the stud 346, mounted upon the crank-arm 228 at the right-hand end of the main shaft and hereinoefore referred to, andis so shaped as to im parta peculiar and intermittent movement to the lever 417 during the operation of the main shaft. To this end an approximately horizontally extending cam portion 419 is provided atthe rearend of the upwardly-deflected or arch-shaped portion of the lever, which imparts an initial lifting movement to the lever, and immediately contiguous to this portion 419 is formed a cam portion 420, which is concentric with the axes of the main shaft when the lever has reached the end of its initial movement, thereby providing for a dwell in the movement of the lever 417.until the stud 346 reaches an inclined cam portion 421, when it is again lifted a short distance, the cam-stud finally passinginto engagement with a second concentrically-curved portion 422, which permits the lever to remain stationary during the remainder of the advance stroke of the crank-arm and until the latter has returned to the inclined portion 421. The intermittent lifting of the lever 417 is so timed as to bear a definite relation to the operation of other parts of the mechanism, as will hereinafter appear.

In the operation of the machine when printing the successive items the pinions of the accumulatorshafts are thrown into mesh with their respective racks at the beginning of the upward movement of the crank-handle, so that the accumulators are rotated during the advance movement of the main shaft. To accomplish this, the extreme end surface of the timing-lever 417 is made inclined, as indicated at 423, and the bracket member 416 is provided with upper and lower cam projections 424 and 425, separated by aninterval or opening 426, which fingers or projections are adapted to be acted upon by the inclined cam-shaped end of the timing-lever to oscillate the rock-shaft in a direction to throw the accumulators into mesh against the tension of a spring 427, tending to normallyhold them in disengaged position. The lower finger 425 of the bracket is somewhat shorter than the upper finger 424, and the end of the lever normally stands in position to engage the extreme end of said lower finger, so that upon the initial upper movement of the timing-lever the lower finger will. be engaged and the accumulators thereby thrown into mesh, the dwell of the lever 417 permitting the latter to rest in holding engagement with the finger 425, and thus retaining the racks in mesh during the full upper movement of the slidingframes and connected racks. Upon the secondary upper movement of the lever 417 the end thereof passes out of engagement with the lower finger of the bracket and .into the recess between the upper and lower fingers, or, in other words, does not engage the depending portion of the upper finger of the bracket, and as soon thereafter as the lever passes out of engagement with the lower bracket-finger upon its upward movement the rock-shaft is freed and the spring acting upon the group of accumulators throws them out of mesh. Upon the return movement of the lever the lower edge of the latter strikes the downwardly and outwardly inclined upper surface 42b of the lower bracket-finger,

and is thereby forced over the end of the finger cam-fashion, it being understood that the lever is of resilient material, so as to be capable of yielding laterally for this purpose and another purpose,which will now be explained.

In order to insure the positive return of the lever to its lowermost position, a lip 429 is provided at its lower side in position to be engaged by the stud 346 as the latter approaches its limit of downward return movement.

When the total is to be printed, the operation is accomplished by actuating the sliding frames through the medium of the acoumulators, and in this case the accumulators are held out of mesh during the upward movement of the sliding frames and racks and thrown into mesh with the latter upon the return or downward movement for the purpose of clearing or returning the accumulators to their Zero positions. In order to accomplish this latter movement, mechanism is provided as follows: Referring to Figs. 1 and 5, 430 designates a total-key generally similar to the numeral-keys arranged at one side of the latter, as best indicated in Fig. 5, and likewise arranged to act upon a bell-crank lever 431, pivotally mounted upon a suitable standard or bracket 432. lower arm of the lever 431 is pivotally connected with an actuating-bar 433, which extends longitudinally and rearwardly to the rear end of the machine, at which point it is connected with a depending link 434, rigidly mounted upon a suitable support 435, which is in turn pivotally mounted between the main side frame. At a point intermediate its length and approximately transversely opposite the rock-shaft 413 said actuatingbar is provided with a wedge-shaped cam projection 436, which is arranged to act upon an The end of the lOO upstanding arm 437 to force the same laterally during the forward movement of said actuating-bar or that movement produced by depressing the total-key 430. The arm 437 has a lower horizontal extension 437, which is secured to or formed as a part of a transversely-extending bar or rod 438, which is guided in suitable ways or bearings in the lower part of the main frame and is provided at its opposite end, or at that side of the machine remote from the actuating-bar 433, with a forwardly-extending arm 439, (see Fig. 2,) which terminates in an upstanding portion 440, (see Fig. 6,) which extends inside of and adjacent to the free end of the lever 417. When the rod 438 is shifted endwise through the action of the cam projection 436, the upstanding arm 440 forces the yielding end of the lever 417 outwardly far enough to carry it out of alinement and permit it to pass the lower bracket-finger 425 during the initial upward movement of the lever. Upon the secondary upward movement of the timinglever, however, the end of the same engages the depending portion of the upward bracketfinger and oscillates the rock-shaft so as to throw the pinions and racks into mesh, it being understood that this secondary movement occurs just after the completion of the upward movement of the sliding frames. Upon the return movement of the main shaft it is to be noted that the timing-lever remains in its uppermost position by reason of its frictional engagement with the bracketfinger until the cam-stud 346 on the crankarm engages the lip 429, and thus carries the lever positively downward; but before this latter engagement takes place the sliding frames will have reached their lowermost positions and the accumulators have accordingly returned to zero. A description of the mechanism and operation thereof by which the totals may be taken from the accumulators by the movements last described is now in order.

The normal position of the accumulators upon their several shafts is that shown in Fig. 1, in which position they are shown at the limit of their forward movement. Immediately below each accumulator when in its normal or forward position is mounted a sliding rack-frame, (designated as a whole 441,) which is supported to slide longitudinally upon pairs of guide-bars 442, secured at their ends to transverse bar members 443 and 444, it being understood that there is one of these rack-frames for each accumulator and that they are free to move independently of each other. Upon the lower side of each rackframe is mounted a rack 445, which is arranged to intermesh with an intermediate segment 446, the several intermediate segments being journaled upon a suitable transverse shaft 447, having its ends supported in suitable brackets 448, rising from the baseframe, as best indicated in Fig. 1. Each segment is also arranged to intermesh at its lower part with a rack 449, formed or mountupon the rear side of the corresponding sliding frame 301, so that movement of the rackframes 441 is positively transferred to the respective sliding frames. Upon each rackframe 441, at the rear part thereof, is formed or mounted an upstanding lug 450, which is vertically beneath the axis of the corresponding accumulator and is adapted to contact with or be engaged by whichever one of the spirally-disposed lugs of the accumulator which happens to be extending vertically downward. The position of the lug 450 is normally just in rear of the rear end of the accumulator, from which it follows that when the accumulators are shifted rearwardly the several lugs 450 will be engaged and the rackframes carried rearwardly a distance exactly proportional to the relative positions of the several lugs of the accu mulators thus brought into engagementthat is to say, the lugs upon the accumulators are spaced apart such distance as to impart movement to the sliding frames, and consequently to the typecarriers connected therewith, a movement equal to the distance between type-numerals of the carrier, so that if the rearmost lug of an accumulator is in alinement with the stud 450 of the sliding rack-frame the type-carrier will be elevated the full distance of its throw and accordingly broughtinto position to print the numeral 9. Next describing the means whereby said accumulators are shifted rearwardly for the purpose described, 451 designates a pair of arms, one at each end of the confining-frame inclosing the accumulators and rigidly mounted in parallel relation upon a rock-shaft 452, journaled transversely in the lower part of the main frame, conveniently in the lower part of the brackets 448. Each arm 451 is provided at its upper end with a fork or slot 453, which is arranged to embrace and engage a stud 454, mounted upon the corresponding end of the confiningframe referred to, so that motion imparted to the rock-shaft serves to shift the accumulators positivelyand uniformly. In order to actuate said arms 451, one of the latter is conveniently provided with a forwardly-extending wing or finger 455, which projects forwardly alongside one of the cam-levers 230, in the present instance that one at the remote side of the machine as seen in Fig. 1. Upon said cam-lever 230 is mounted a stud 456, which is in position to engage the lower edge of the wing and force the latter upwardly when said cam-lever is oscillated, provided the wing is shifted into vertical alinement with said stud, as now to be described. Normally the wing 455 stands in a position out of vertical alinement with the stud 456, and in order to force it laterally into alinement with the stud at the time a total is being taken the same arm 437 which is acted upon by the inclined cam projection 436 is extended above said cam projection a sufficient distance to engage the outer side of the wing, and force the latter over with said arm. Movement is imparted to the cam-levers 230 by means of the main crank-shaft acting through the crank-arm 22S and stud 229, as hereinbefore fully set forth.

From the foregoing description it will be obvious that the type-carriers will be caused to print the numerals which correspond to the position of the lugs 409 of the respective accumulators which are in register with the lugs of the several rack-frames 441 at the time the total is taken. It will be obvious, however, that a transfer or carrying mechanism must be provided of some kind for cooperating with the accumulators in order that the latter should be brought into proper position in order to so correct totals.

The mechanism shown and described herein is novel and is made the subject of claims in a copending application, Serial No. 95,344, but will now be described herein.

Referring more particularly to the rear end elevation view, Fig. 4, upon the end of each accumulator shaft is rigidly mounted a ratchet-wheel 500, which ratchet-wheels, it will be noted, are of such diameter relatively to the spacing apart of the accumulatorshafts that their peripheries are closely contiguous, but do not interfere with each other. Each ratchet-wheel is provided with ten teeth or ratchet-shoulders corresponding to the digits of each order, and likewise each ratchetwheel is provided with a single stud, as 501, mounted near the peripheries of the wheels and projecting outwardly or in a direction parallel with the axes of their shafts. Upon the main frame, above the ratchet-wheels, is secured a supporting-plate 502, which forms the support upon which is mounted the actu ating mechanism now to be described, said plate being provided in its upper and lower edges with a series of guide-recesses 503, arranged in vertically-disposed pairs, a pair of these guide-recesses being provided in vertical alinement with the space between each contiguous pair of ratchet-wheels. Upon the plate 502 is also mounted a series of sliding pawl-supports 504, each consisting of a plate slightly wider than the width of the guidenotches and provided at each end with an inturned integral lug or guide member, as 505 and 506, engaged with the upper and lower guide-recesses. The lugs 505 and 506 are spaced apart far enough to provide for a limited vertical reciprocation of the pawl-supporting plates upon the support 502, and the lower lugs 506 project inwardly beyond the inner face of the support 502 and are there severally connected with coiled contractile springs507, supported upon lugs 508 upon the inner face of the plate 502 and tending to normally hold the pawl-supports at their upper limits of movement. Upon the outer or rear face of each pawl-support is pivotally mounted a push-pawl 500, which is pivoted so as to oscillate in a transverse plane and is adapted to act upon the subjacent ratchet-wheel to step the latter forward when the pawl-support is depressed in the follow ing manner: Adjacent to each pawl-support and at the left-hand side thereof as viewed from the rear is pivotally mounted a pawlsetting lever 510, which is arranged to depend at its lower end into the path of rotation of the corresponding stud 501 of the ratchetwheel vertically beneath the same, while at its opposite end it is arranged to extend across the pawl-supportin g plate into position to engage the pawl thereon to swing the same toward the right as viewed from the rear, in which latter position the end of the pawl is brought into position to engage and advance the ratchet-wheel one tooth when the pawl is shifted downwardly. The pawls are so mounted upon their pivotal supports as to be frictionally held in whatever position they are left, so that after any given pawl has been thrust over into position to act upon its ratchet-wheel by the engagement of the stud of the ratchet-wheel of next lower order with the lower end of the corresponding pawlshifting lever 510 it will remain in this position until the next printing operation, as will hereinafter appear. It will be noted that in the normal positions of said pawls they stand in such position as to pass between the adjacent ratchet-wheels without advancing the latter, so that it is only those pawls which have been set by the action of the pawl-shifting levers 510, as hereinbefore described, which act upon the corresponding ratchetwheels. It will be further noted as to these latter pawls the rotation of the ratchet-wheel under the action of the pawl serves to return it to its normally vertically depending position, so that upon succeeding operations it will not actuate the ratchet-wheel unless it has again been reset. It may also be noted at this point that the relations of the adjacent ratchet-wheels to each other are such that when the pawl reaches its limit of actuating movement between the latter both adjacent ratchet-wheels will be positively locked against further rotation by reason of the fact that the pawl practically occupies the entire space or is inserted wedge fashion between the two. This is a feature of much importance, inasmuch as it positively prevents overthrowing of the ratchet-wheels and the accumulators connected with the same shafts.

Describing now the mechanism whereby the pawls are actuated and referring more particularly to Fig. 1, 511 designates a rockbar journaled at its ends in the main side frames of the machine to extend transversely across the latter and carrying at one end a depending arm or crank 512, upon which is mounted a wrist or stud 513. 514 designates an oscillatory arm pivotally mounted at its lower end as engaged at 515 to a suitable bracket upon the base-plate and provided at its upper end with a fork or slot 516, operatively engaging the stud 513. 517 designates an actuating-bar connected with the arm 514 at a point intermediate the length of the lat- IIO ter and extending thence forwardly to a point vertically above the main shaft and provided in its forward end with a long slot 518, which is operatively engaged with the stud 329 of the crank-arm 328. The length of the slot 518 is such as to afford considerable lost motion, so that the oscillatory arm 514 is drawn forward a short distance only during the advance.

movement of the main shaft, and this movement occurs practically at the end of the said advanced movement of the main shaft. The return movement of the oscillatory arm is likewise imparted just at the end of the return movement of the main shaft.

Referring more particularly to plan view Fig. 2, 519 designates a series of levers, one for each of the several accumulators,arranged to extend longitudinally of the machine and journaled at their forward ends upon a cross bar or shaft 520, said levers being conveniently spaced apart,so as to be held in register with the several lugs 406 of the pawl-supports by means of spacing-sleeves 521. Each lever at its rear end rests upon the corresponding inwardly-extendinglug 506 of one of the pawlsupports,so as to depress the latter when the lever is depressed. At a point intermediate its length each lever 519 is provided with a stud 522, and the rock-bar 511 is provided with a corresponding series of cam-wings 523,severally adapted to engage the studs 522 and force downwardly the levers when the rock-bar is oscillated by means of the arm 514, as hereinbefore described. The cam-wings 523 are disposed in different angular relation to the axis of the rock-bar 511, each wing from the right -hand side or units order toward the opposite side being behind the preceding one relatively to the forward direction of movement of the rock-bar, so that the levers 519 are depressed consecutively. The object of this arrangement is to insure a proper carrying from one accumulator to the next. For example, it all of the accumulators should happen to stand in position to record the numerals 9 the addition of one unit would necessitate the carrying across the entire series,and by reason of their consecutive operation this would be properly accomplished. The shape of the cam-surfaces 524 of the several wings is such as to impart a relative rapid downward movement to the levers and to thereafter retain the latter depressed during the entire advance movement of the rock-bar. The springs 507 acting upon the pawl-supports obviously return the levers and hold them in their normal upper positions;

After the total has been taken the accumulators are thrown into mesh with their respective racks, while the rack-frames are in the positions occupied during the printing of the total, and upon the return or downward movement of the rack-frames the accumulators are therefore returned to zero, as hereinbefore described. It will be obvious that this necessitates a reverse rotation of the accumulators and the ratchet-Wheels mounted upon their respective shafts. In practice it is desirable to provide centering-pawls 525, which are mounted to reciprocate vertically in suitable bearings 526 and 527 upon the main frame vertically beneath the respective ratchet-wheels and arranged to act upon the latter to insure the accurate stopping of said wheels to bring their several lugs 409 in exact alinement with the engaging lugs of the sliding rack-frames 441. In order to retract these centering-pawls during the operation of clearing or returning the accumulators to zero, the support 435, upon which the de pending link 434 engaged with the actuatingbar which transmits motion from the totalkey dismounted, is in the form of a rock-bar journaled between the main side frames of the machine, and upon this rock-baris mounted a series of fingers 528, which project rearwardly and engage collar-like projections 529 upon the centering-pawls, hereinbefore referred to, and operate to depress the latter when the total-key is depressed against the tension of spiral springs 530, interposed between said projections 529 and thelowerguidesupports 527 of said pawls.

As hereinbefore stated, the present invention includes certain improvements in the construction and arrangement of the keyboard, which while specially applicable to the present type of machine may nevertheless be employed in other connections.

Referring more particularly to Fig. 1, 600 designates as a whole a base-board, which is arranged to cover the underlying key mechanism and is preferably inclined upwardly and rearwardly in the usual manner to facilitatetheoperatorsviewofthekeys. Through the keyboard, which is suitably supported upon the main frame or casing, are arranged to extend the staffs 601 of the keys, ihelower ends of these staffs being provided with contacting portions 602, adaptedto engage the respective key-levers 206, hereinbefore described. In the preferred construction shown the said baseboard 600 forms the guide through which the key-staff reciprocates, and to this end it is made of substantial thickness, asindicated in the drawings, so that the guideapertures 603 therethrough serve to accurately guide and confine the keys. Preferably, and as shown herein, the several keys are of sheet metal struck out by means of'suitable dies to form the flat-bar-llke staff portions 601, horizontally-extending contact portions 602, and bent-over or horizontally-extending key-tips 604, all in one integral piece. The key-tips are of peculiar and novel construction, being constructed in the form of rings, as best indicated in plan view, Fig. 5, which ring members are suitably rounded at their up per sides and particularly at their inner upper portions, so as to comfortably accommodate the finger-tips of the operator. The object of thus constructing the finger-tips in ring form is twofold-namely, to facilitate a clear inspection of the keyboard thereunder, but 

